Drafting board



M. P. HITE DRAFTING BOARD Oct. 21, 1952 2 SHEETS-SHEET 1 IN VENTORMelville I? H its Filed Dec. 7, 1948 ATTORNELQ Oct. 21, 1952 Filed lies.7, 1948 MQP. HlTE DRAFTING BOARD 2 SHEETSSHEET 2 INVENTOR Melville'PHLte I Q PQ ATTORNEYS Patented Oct. 21, 1952 UNITE-D STATES PATENTOFFICE mmrrme some MeIV'iII'e '13 r'Hite, Jacksonville, Fla.fimflfcagfibh bebember 7, 1'94s, 'seria1Nmts'a'sts 1 "Claim.

' gu'rdi ng ams are mere" bnvement for' use andare straightedge andtriangle guiding aids shifted straightedge and a modified means forclamping it to the base member.

Fig. 6 is a view taken on line 6-6 of Fig. 5. Fig. '7 is a view taken online of Fig. 5. Fig. 3 is a detailed view of one end of the straightedgeand illustrating a modified form of means for clamping it to'the basemember.

Fig. 9 is a view taken on line 99 of Fig. 8. Fig. 10 is a detailed viewof one end ofthe straightedge andillustrating a further type of meansfor clamping it to the base member.

Fig. 11 is a view taken on line I I-l l of Fig. 10. Fig. 12 is a viewtaken on line |2l2 of Fig. 10. In the embodiment of the inventionillustrated in Figs.v l, 2, 3 and 4 I have provided a base memberdesignated by the numeral I. This base member may be formed of anysuitable substantially rigid material to present a fiat surface forsupporting paper and the like adapted to be written, drawn or otherwiseworked on. Removably mounted on the upper working fiat surface of thebase member is a straightedge element 2 which may consist of a strip ofwood or other suitable material of suflicient strength to provide thenecessary rigidity. As will become apparent as this description of myinvention proceeds one or more strips ofpaper 3 are clamped along oneedge between the straightedge and the base member so that the paper issubstantially immovably positioned relative to the base member. A commondrafting triangle l is illustrated positioned and oriented against theupwardly extending flange like edge of the straightedge element 2. Itwill be recognized that the triangle 5 takes orientation from thetriangle 4. It will be understood that the guiding aids provided by thetriangles may be moved along said straightedge and retain orientation,and also those guiding aids may be combined otherwise and with otherguiding aids and that all may take primary orientation from the upwardlyprojecting flange like edge of said straightedge element 2.

The straightedge element 2 is reciprocally as well as removably mountedon the base member I so that it may be moved from position clamping oneor more papers between it and the base memher and to unclampingposition. The means for selectively clamping and unclamping thestraightedgeto the base member includes a recess 6 formed through thestraightedge and a bifurcated inclined plane or opposed spaced apartinclined shoulders 8. It will be apparent from the drawings that theshoulders 8 do not extend the full length of the recess so that anopening 8' is provided which is wider than the space between theshoulders-8. I provide a straightedge retaining means in the form of ascrew 9 which is screwed into the base member in such a manner that itprojects angularly therefrom. The screw includes a head rigidly formedwith the shank of the screw so that the undersurface of the head of thescrew presents an inclined plane surface 9'. It is preferable that theangle of inclination of the surface 9' on the under side of the screwhead to the perpendicular be substantially equal to the angle ofinclination of shoulders 8 to the horizontal.

When the straightedge is operatively positioned onthe base member thescrew 9 projects into the recess 8 in the straightedge and the head ofthe screw projects above the shoulders 8 so that the inclined planesurface 9 of the head is in position to ride up on the inclined plane 8.The wide opening 8' permits the straightedge to be removably attached tothe base member for the head of the screw may pass through the wideopening.

When the strai'ghtedge is reciprocated relative tothe base member byslidable motion the inclined plane or surface 9' on the lower surface ofthe screw head will reciprocally cooperate with the inclined plane orshoulders 8 and these inclined planes tendto engage or disengage toproduce a wedge like clamping action between straightedge 2 and basemember I, The incline of the inclined planes being quite flat a smallrotation of the straightedge about the vertical axis of the screw doesnot sensibly decrease the efiect of the clamping action, though a largerrotation greater than that indicated in Fig. 4 tends to render itinefiective Rotation of the straightedge element establishes new axes ofprimary orienta tion for guiding aids and has considerable value inpractice. I a I It is obvious that a plurality of such clamping means asis above described may be provided, and two such are shown in Fig. l.The purpose of a plurality is to extend the clamping action effect onthe edge of a sheet of paper, and, also to provide a fixed axialalignment for the straightedge element 2. The bodies of a plurality ofscrews form guides for the axial alignment of a sheet of paper or othermaterial. Thus with a plurality as described the sheet of paper may beheld to a certain orientation while the straightedge element 2, may berotated to various positions and later returned to its originalposition, whence lines related to many different axes may be drawn onthe same sheet of paper.

In the embodiment of my invention illustrated in Figs. 5,6 and 7 I haveused the same reference numerals to describe similar parts. In this formof my invention Ijhave departed fromthe-form sho'wn'in Figs. 1 through 4only by using a substantially fiat orphilister screw head I!) having atapered underhe'ad I I which rides on the inclined planes provided byshoulders 8 .On the straightedge. Thus, the inclined planes engage witha very small contact area and along substantially vertical axial areas.The effect of this is to permit rotation of the straightedge element 2to practically any angle without much reducing the effect of theclamping action.

In either of the above described embodiments of my invention it isobvious that the screws olfer a ready means of adjusting the effect ofthe clamping action. It isalso obvious that when moved to the limit thestraightedge element may be lifted free from the board element andreadily restored to its form position. It is also within mycontemplation in certain adaptations of my invention to reverse theparts, that is the screw would projectfrom the straightedge into arecess providing inclined shoulders which would be form d in t e esemember. I

used the same reference characters. The straightedge is formed with arecess 6 and a tongue or the like l2 projects into the recess from anend wall thereof. This tongue is formed with an inclined upper surfaceI3 adapted to function in generally the same way as the shoulders 8 inthe prior described forms of my invention. A suitable spring element I4is fastened to the base member I and is adapted to project therefrominto the recess 6. The spring element includes a projecting portion l5,the under surface of which is adapted to form an inclined planereciprocal to and cooperating with the inclined plane formed by theupper surface l3 of tongue l0. Thus, slidable motion betweenstraightedge 2 and base member 1 effects a wedge like clamping action,clamping or unclamping the straightedge and base and also any part of asheet of paper between them. The rising part iii of spring element l4forms a positive guide for positioning a sheet of paper.

In Figs. 10, 11 and 12 I have illustrated a further form of myinvention. In this form the wedge like clamping action between thestraightedge and the base member occurs between a suitably undercut bodyI! which is rotatably secured to the base member I by a single screw,rivet or the like l8 and the body I! is adapted to project into recess 6formed in straightedge 2.

The body I! is of tapering or wedge like construction presenting anarrow end l8 and a wide end IS. The recess 6 is of tapering formcomplementary to the shape of body I! and the walls 20 of the recess areinclined inwardly and downwardly to properly coact with the undercutsides of the body. Thus, the straightedge element 2 may be rotated toany angle without effecting the clamping action.

The forms of my invention illustrated in Figs. 8 thru 12 also providefor removal of the straightedge from the base member.

Having described my invention, I claim:

A drafting board, including a base member, a straightedge elementremovably attached to said member. said straightedge element havingslots therein, retaining means rigidly attached to said member andprojecting therefrom at an acute.

angle thereto and extending through the slots, enlarged heads rigidlyfixed on the ends of the retaining means which extend through the slots,said heads having inclined plane surfaces thereon, and complementaryinclined plane surfaces on said straightedge element positioned thereonfor wedging engagement with the inclined plane surfaces on said heads toclamp said straightedge element to said base member by a slidingmovement of said straightedge element relative to said base member, andsaid slots being widened at one end to permit passage of said headstherethrough, whereby said straightedge element may be removed from saidbase member.

MELVILLE P. HITE.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 370,409 Podgorski Sept. 27, 18371,195,817 Hormes Aug. 22, 1916 2,015,247 Tindal Sept. 24, 1935 FOREIGNPATENTS Number Country Date 404,323 France Oct, 16, 1909

